Chicago River Dyed Green For St. Patrick’s Day [Gallery]

Chicagoans will tell you that the Chicago river is nearly always green. But on St. Patrick’s Day, it’s on purpose.

Thousands of people gather in downtown Chicago during St. Patrick’s Day weekend to watch as city workers add a little bit of Irish to the city’s waters.

Why do they do this? Well, it all started on accident.

The Inquisitr reported earlier (check out some more St. Patrick’s Day facts here) that the city accidentally dyed the river green about 50 years ago. Plumbers were working on city pipes to find out if any illegal sewage was being dumped into the river. They used green dye to trace the water and eventually ended up turning the river green.

But instead of admitting that they had made a mistake, the plumbers union proudly declared that they were dying the river green for St. Patrick’s day. And that’s how the tradition was born. Chicago plumbers are still responsible for turning the city’s river green (of course, they do it on purpose now) every year.

So how is it done? Well, that’s top secret plumbing information right there.

Bill King, one of the few who knows the secret, told CBS Chicago: “There have been over a hundred cities that have contacted the plumbers trying to find out how to do it, but we’re not sharing that … Because it wouldn’t be unique. Everybody knows about Chicago dyeing the river there are thousands of people down here. It is a very unique Chicago thing.”